When to worry about dark urine with dehydration

When the body has less fluid available, the kidneys conserve water and urine becomes more concentrated. It may look darker and be passed less often. Dark urine can also have other causes, including blood, liver or kidney problems, and some medicines, so a colour change that does not improve with sensible rehydration should be checked.

Move to a cool place, rest, and take frequent small sips of water or an oral rehydration drink. If vomiting or diarrhoea is present, ask a pharmacist or clinician which rehydration product is suitable. Avoid alcohol, and do not force large amounts of fluid if you have been told to restrict fluids.

Arrange medical advice if urine remains very dark, you are passing very little urine, or dizziness and weakness continue despite drinking. Seek emergency care for fainting, confusion, severe abdominal or back pain, inability to keep fluids down, or red or cola-coloured urine.

Ask how much and how often to drink for your situation, whether medicines or kidney conditions affect your fluid plan, and whether a urine or blood test is needed if the colour persists.